The present invention relates to an outboard jet drive boat and especially to an outboard jet drive having an engine and jet drive mounted in a housing which is removably attached to the transom of a boat hull.
There have been several proposed types of outboard set drives for watercraft but most are similar to an outboard motor in which the outboard motor propeller and lower unit have been replaced with a jet drive. The jet drive includes a jet pump in the lower unit that operates so as to provide propulsion force for a watercraft. There are advantages in employing jet pumps for propulsion units as opposed to propellers. The jet drive permits operation in shallower water and also the propeller is shrouded and there is less likelihood of injury. There has been a variety of proposed constructions for outboard jet drives for positioning the jet pump in different positions relative to the hull transom and bottom of the transom but in a typical jet drive, the engine and jet drive are located directly in the hull with an opening in the bottom of the hull for capturing water passing under the hull and then utilizing the jet pumps to thrust the water out the rear of the hull to propel the boat. Outboard jet drive units are made similar to typical outboard motors with a motor driving a drive unit which operates a jet drive unit.
Prior art outboard liquid jet propulsion units can be seen in the Nanami U.S. Pat., No. 5,536,187, for an outboard jet drive for watercraft in which the jet propulsion unit is disposed forwardly of the transom and beneath the undersurface of the hull for improving its pumping efficiency while the motor is attached to the transom of the boat. In the Jordan U.S. Pat., No. 4,459,117, a liquid jet propulsion unit is driven by a conventional outboard motor. The drive of the motor directly rotates an impeller which draws water into the impeller chamber and through an outlet chamber and nozzle to drive the craft forward. In the Miyamoto U.S. Pat., No. 4,457,724, an apparatus for driving a surfboard includes an internal combustion engine mounted in a box which is mounted on the rear portion of the surfboard. A water jet propelling device is driven by the internal combustion engine for propelling the surfboard. The exhaust gas system in the water jet propelling device is positioned in the box. In the U.S. Pat. to Boyer et al., No. 4,942,838, an inflatable watercraft has a portable engine package. The engine package includes an internal combustion engine mounted in a thin fiberglass hull. The base plate of the hull includes a water inlet scoop for feeding water to the pump and an exhaust port for exhausting the water. The pumps high pressure water outlet is pointed in the aft direction above the water line to propel the craft by the reaction force resulting from the high velocity water jet. In the F.C. Clark U.S. Pat., No. 3,055,175, a marine propulsion unit takes a conventional outboard motor and replaces the prop unit with a marine jet motor using a pump to issue a jet of water to propel a boat. The Parker U.S. Pat., No. 5,356,319, is for a boat with a removably inboard jet propulsion unit in which the integral jet power unit is encased in a waterproof housing and positioned in a well located in the hull and is mounted to be removed from the hull.
The present invention is directed towards an outboard jet boat in which the main fuel tank and controls are mounted within the hull of a boat while the outboard jet drive unit is mounted in a housing with an engine and is removably attached to the transom of the boat. The fuel tank and controls are connected between the hull and outboard drive through quick disconnect couplings. The housing is shaped to support an engine on a platform directly over the jet drive unit for actuating the jet drive unit through a clutch mechanism with the engine and jet drive positioned parallel to each other.
An outboard jet drive boat apparatus has a boat hull having a transom and having a removably attached outboard jet drive attached to the transom. The outboard jet drive includes a housing sealed against the intrusion of water and has an engine mounting platform therein having an engine mounted thereon on flexible engine mounts. The housing has a sealable entrance through the top thereof and is removably attached to the transom of the hull. A jet drive unit is attached in the housing below the engine supporting platform and extends generally parallel to the engine from the front of the housing and through the rear of the housing. The jet drive unit is operatively attached to the overhead engine through a clutch mechanism. A main fuel tank is positioned inside the hull and is connected with a fuel line to an auxiliary fuel tank inside the housing and the auxiliary fuel tank is connected to the engine for feeding fuel to the engine. The fuel pump is mounted in the housing to pump fuel to the engine from the auxiliary fuel tank and from the main fuel tank to the auxiliary fuel tank. Electrical controls are located in the hull and coupled through the housing to the engine to control the engine and jet drive unit. Quick disconnect couplings allow the fuel line and control lines to be rapidly connected and disconnected to the outboard drive unit.